COMEDK · Physics · 9. Gravitation
The radius of a planet is twice the radius of earth. Both have almost equal average
mass-densities. \(v_{p}\) and \(v_{e}\) are escape velocities of the planet and the earth, respectively, then
- A \(v_{p}=1.5 v_{e}\)
- B \(v_{p}=2 v_{e}\)
- C \(v_{e}=3 v_{p}\)
- D \(v_{e}=1.5 v_{p}\)
Answer & Solution
Correct Answer
(B) \(v_{p}=2 v_{e}\)
Step-by-step Solution
Detailed explanation
The escape velocity of earth, \[ v_{e}=\sqrt{\frac{2 G M_{e}}{R_{e}}}=R_{e} \sqrt{\frac{8}{3} \pi G \rho_{e}} \] Similarly for a planet, \[ v_{p}=R{ }_{p} \sqrt{\frac{8}{3} \pi G \rho_{p}} \]…
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